SELECT 
  1 
FROM 
  cscart_lock_keys 
WHERE 
  key_id = '2adf4e211a339736af4fa831503f1665ae37cbf134ffefb13a2160749c032ee6' 
  AND token = '/JjPiD1sn3ZvyyGC31h9ZtaLlFttt1m+SQ9tFjJfyPY=' 
  AND expiry_at > UNIX_TIMESTAMP(NOW())

Query time 0.00023

JSON explain

{
  "query_block": {
    "select_id": 1,
    "message": "no matching row in const table"
  }
}